Channeling apparatus and method

ABSTRACT

A jet flame rocket burner for working rock and other spallable mineral material. Channels are formed in rock masses by opposing jets moved over the surface of the rock.

United States Patent Inventor Ernest Marshall Fitzgerald Norwich, Vt.

May 3, 1968 Aug. 3. 1971 Browning Engineering Corporation App]. No. Filed Patented Assignee CHANNELING APPARATUS AND METHOD 2 Claims, 4 Drawing Figs.

US. Cl .i 299/ 14 Int. CL EZlc 37/06 Field of Search i. 125/1;

[56] References Cited UNITED STATES PATENTS 3,245,721 4/1966 Margiloff 125/1 X 2,78 l ,754 2/1957 Aitchison 125/! FOREIGN PATENTS 203,118 3/1966 Sweden 299/14 Primary Examiner- Harold D. Whitehead Attorney-Wm. O Moeser ABSTRACT: A jetlflame rocket burner for working rock and other spaliable mineral material. Channels are formed in rock masses by oppsing jets moved over the surface of the rock.

CHANNELING APPARATUS AND METHOD My invention relates to the working of mineral masses, and

is more particularly directed to improvements in channelling.

The conventional technique for flame channelling rock is to produce an essentially up-down motion of the burner to produce a continuous slot, or channel. This method arose naturally from the previous practice of drilling vertical holes side-by-side. Channelling in thisway has several serious limitations that my invention eliminates. These improvements will be better understood from the figures, where:

FIG. 1a is a longitudinal sectional view of one embodiment of my invention.

FIG. 1b is a lateral cross-sectional view of section A-A of FIG. la.

H0. 2 is a view of the conventional flame channelling method. 4

FIG. 3 is a second embodiment of the invention.

Referring now more particularly to FIG. 10, internal burner 11 is held by tube 12, is supplied with oxidizer (either oxygen or compressed air) and fuel through hoses 13 and 14 respectively. Burner 11 is an internal combustion device capable of producing supersonic flame jets, described fully in U.S., Pat. No. 3,463,249, issued Aug. 26, I969, to James A. Browning et al. A portable track 15 is ositioned along the line of the channel to be formed. On this track rides carriage 16 which supports tube 12 by a guide 27 and a pinion gear 17. Gear 17, together with a rack 18, provides the means to lower the burner 11 into the channel as cutting progresses. Carriage 16 is most conveniently electrically powered to move along track 15. The tip of burner 11 is'held slightly above or lightly against the bottom of channel 20. The burner 11 moves along the channel at a rate which will cause the removal of a layer of 1 thicknessfd" from the channel bottom..d" varies depending on the rock type and structure, but is preferably between onefourth and 4 inches.

Rock separation at point 22 from the rock mass 19 is caused by differential expansion of the rock due to the temperature gradient imposed by high-velocity'jet 21; The spallings, so produced are ejected in stream 23 from channel 20.

FIG. lb showscarriage 16 riding on wheels 25 on track 15. Track 15 is held by support legs 24. Electric motor 26 drives pinion gear 17 poviding the vertical motion to reposition 'bumer 11 at the end of each traverse along the bottom of channel 20.

Horizontal motion of the burner to produce a channel has several major advantages over the conventional method practiced and which is shown in FIG. 2. Conventional channelling provides for motion of burner 32 up-and-down the forward face 34 of channel 31 as shown by arrows "M,." Jet flame 33 issues through a nozzle (not shown) which is angled away from the burner centerline toward the rock face to allow direct impingement of jet 33 against rock 19 as shown. This method has three major disadvantages. First, the oerator has difficulty viewing the actual cutting zone due to his view being blocked by the burner 32. Second, the horizontal thrust component F,," of flame jet 33 makes support of burner 32 difficult. It will be seen from FIG. 2 that when the jet 33 is so directed against the rock face the reactive thrust of that jet soduces two force components-one essentially vertical and tending merely to reduce the effective weight of the unit, and the other component tending to swing the unit away from the rock face along the line F As a result, the unit is not balanced, but tends to separate from the'rock face. For this reason, deqs channels are very difficult to make. Third, it is common for large spallings to separate from the channel walls at a point removed from the advancing burner. This is shown in FIG. 2 by the dotted lines where spalls 35 falls to the channel floor effectively blocking the flow 36 and directing said flow as 37 uward often directly at the operator. When channel blockage occurs channelling is halted and spalls 35 must be removed by mechanical leans.

This is a time consurning and therefore expensive task.

My method eliminates these disadvantages. Viewing the working zone is simple. The horizontal thrust component can be completely eliminated by using a. dual-jet burner to be hereinafter described. Large spalls do not (indeed cannot) fall from the working point to block further progress.

The most convenient way of eliminating the horizontal thrust F of FIGS. 1a and 2 is to use a burner 40 of FIG. 3 which has opposing flame jet streams 41 and 42. With these jet streams in oposition, and being equal, the horizontal thrust components along the line M3 are cancelled and the unit is in balance. In addition, the vertical thrust component acts to reduce the weightforces acting on carriage 16. Thus, deep channels are conveniently produced. If such 'a balanced burner were used in the conventional way of FIG. 2, it is clear that one-half of the cutting energy would be wasted, because the second jet will simply expend itself in the air. In my device, both jets work effectively against the rock mass. As shown in FIG. 3 each jet 41 and 42 acts separately to remove a layer of rock 19. In this case, the burner 40 is moved over the surface of the rock mass along the line of arrow M3. In practical application, the burner (on its carriage) traverses the path along which the channel is being cut and works in both directions, the jet 41 first leading and then trailing the jet 42. Both jets operate continuously against the rock mass for maximum efficiency. In this way channelling speeds nearly double those possible with a single jet flame as possible. The same mass flow of flame reactants, if made to form a single flame jet, would produce an undesirably wide channel due to its larger jet dimensions.

The principles of the invention are also applicable to trepanning by producing circular channels as required in tun nelling and shaft work. Also, the use of an abrasive particle flow in the jet stream for cutting nonspallable rock is also contemplated, as shown and described in the patent to Browning et al. referred to above.

lclaim:

1. Apparatus for removing material from rock masses to form a channel therein comprising a carriage for traverse horizontally along a selected path on the surface of said mass; an internal burner mounted on said carriage and adapted to produce a pair of opposing flame jets issuing along the line of said selected path and both directed obliquely downwardly against said mass; and means for lowering said burner into said channel as cutting thereof by said flame jets progress on suecessive passes of said carriage across the surface of said mass.

2. A method of forming channels in a rock mass comprising burning a fluid fuel with an oxidant in an internal burnerto form a pair of flame jets; directing the first of said jets in a generally horizontal direction but titled downwardly against the horizontal surface of said mass; directing the other of said jets in a generally horizontal but opposite direction to said first jet and also tilted downwardly against said mass; moving said burner in the line along which said jets are directed and in successive passes along the top surface of said mass to form a channel therein, and lowering said burner into said resulting channel as cutting thereof progresses so that said jets continue to impinge upon and work the bottom horizontal surface of said channel. 

1. Apparatus for removing material from rock masses to form a channel therein comprising a carriage for traverse horizontally along a selected path on the surface of said mass; an internal burner mounted on said carriage and adapted to produce a pair of opposing flame jets issuing along the line of said selected path and both directed obliquely downwardly against said mass; and means for lowering said burner into said channel as cutting thereof by said flame jets progress on successive passes of said carriage across the surface of said mass.
 2. A method of forming channels in a rock mass comprising burning a fluid fuel with an oxidant in an internal burner to form a pair of flame jets; directing the first of said jets in a generally horizontal direction but titled downwardly against the horizontal surface of said mass; directing the other of said jets in a generally horizontal but opposite direction to said first jet and also tilted downwardly against said mass; moving said burner in the line along which said jets are directed and in successive passes along the top surface of said mass to form a channel therein, and lOwering said burner into said resulting channel as cutting thereof progresses so that said jets continue to impinge upon and work the bottom horizontal surface of said channel. 